Retina

eye, we must first know how the eye itself functions and why it is important to have the macula intact. A heathy eye is made of different layer that helps people to see colors, movement and to see images plainly. The macula is part of the retina, the retina is

the eye. These segments are optic nerve, optical system and retina. Their roles are explained below. Eye sight process Phase 1: During the initial phase, optical system is activated. Optical system is placed in the frontal eye area. Parts of the optical system are lens and cornea, and their role can be compared with the role of lens on a camera. They gather and focus the light on the retina in order to create a picture. Phase 2: Retina is placed in the back side of the eye and it has to „collaborate“

the retina. The ability to view far away objects requires that the light be refracted less and will result if the light from the far away object is refracted more than what is necessary. If the lens swells more than its normal, then it will tend to refract the light rays more than normal. This tends to cause the images of far away objects to form at a location that is in front of the retina. This can also occur if the eyeball is extended in the horizontal direction, and can cause the retina to be

The eyeball holds many parts to allow eyesight. The retina holds the key to allowing the human eye to see color. The pupil appears as the black part of the eye that people see, the pupil however does not have much to do with comprehending color. As Clarence Rainwater said in his book “The pupil is simply the hole in the iris through which light enters the eye.” (84) The light then has to pass through many parts of the eye before reaching the retina such as the transparent cornea, the aqueous humor

The visual system contains two types of photoreceptors called rods and cones. They are distinguished from one another by their shape, which also gives them their names, and the types of photopigments they contain, how the spread across the retina, and the differences in their synaptic connections (Purves, Augustine, Fitzpatrick, Katz, LaMantia, McNamara & Williams, 2001). Rods are found in the periphery of the eye and react to faint light, including black and white which allows twilight vision. Cones

In the control group, the β-cells were pale stained and located centrally surrounded by the α-cells. The Islets were fairly numerous surrounded by the sero-acinar cells which were well stained and comprised of the exocrine component of pancreas. In the diabetic group, there were necrotic and atrophic features in most β-cells of Islets of Langerhans and vacuoles were present. There was a marked reduction in the number of islets. Following treatment with 400 mg/kg of fenugreek + 250 mg/kg of metformin

characteristics of the object. When you look at a banana, the wavelengths of reflected light depending on what color you see. The light waves reflect off the banana peel and reaches the retina at the back of your eye. That's where cones come in. Cones are one type of photoreceptor, the tiny cells in the retina that respond to light. When light from the banana reaches the cones, it changes them to different levels. The outcome is split along the optic nerve to the visual cortex of the brain, which

mainly of the cornea, lens, pupil, iris, retina, fluid-filled chamber, and the optic nerve. The cornea is a clear tissue that covers the front of the eye. The lens is a flexible structure that focuses light. The layer of receptor cells that line the back of the eye is called the retina. The pupil is the opening through which light enters the eye (Coolidge-Stolz, E. & Graff-Haight, D. 2000). The eye responds to a stimulus of light. Receptors in the retina convert the light stimulus into electrical

Explain how that stimulus is processed from the retina to the visual cortex of the brain. Focusing an image clearly onto the retina is the initial step in the process of vision, but although a sharp image on the retina is essential for clear vision, a person does not see the picture on the retina. Vision occurs not in the retina, but in the brain. Before the brain can create vision, the light on the retina must activate the visual receptors in the retina by a two-element

Age-related Maculopathy, AMD, ARMD, and Macular Degeneration. ARMD is categorized into two forms; wet or dry. The dry form is more common and accounts for 85-90% of all cases of ARMD and is caused by a buildup of yellow deposits called drusen under the retina and causes vision loss over time. The wet form, on the other hand, is caused by the growth of abnormal blood vessels that leak blood and fluid under the macula which causes rapid vision loss. The genetic changes involved with ARMD are concentrated